Methods for making reinforced thermoplastic composites

ABSTRACT

Methods of forming multi-component reinforced composites are described. The methods may include forming a particle-reinforced component and a polymer-containing component where the particle-reinforced component and the polymer-containing component are in contact with one another. The particle reinforced component may be formed by a process that includes providing reactive particles that have a reactive polymerization promoter chemically bonded or coated on the surface of the reactive particles and contacting the reactive particles with a resin solution that includes monomers of a polymer. The polymerization promoter chemically bonded or coated on the surface of the reactive particles may promote the polymerization of the monomers. The resin solution may subsequently be polymerized forming a polymer matrix around the reactive particles.

Reactive sizing compositions for fibers and flakes are described thatallow the fibers and flakes to participate in polymerization reactionswith resin compositions to form fiber (and/or flake) reinforcedcomposites. The composites may be used in a variety of applications,including building materials such as reinforced mats, tubing, and partcomponents, among other applications.

BACKGROUND OF THE INVENTION

Forming processes are used to make large and/or structural glass fiberreinforced composite (GFRC) parts. Such processes include RIM (ReactiveInjection Molding), SRIM (Structural Reactive Injection Molding), RTM(Resin Transfer Molding), VARTM (Vacuum Assisted Resin TransferMolding), SMC (Sheet Molding Compound), BMC (Bulk Molding Compound),spray-up forming, filament winding, LFI (Long Fiber Injection molding)and pultrusion.

In the injection molding process, chopped glass fibers and pellets of athermoplastic polymeric resin are fed into an extruder to mix the twotogether at elevated temperature. Substantial working and maceration isimportant and sometimes necessary to wet out the glass fibers at theelevated temperature due to the high viscosity, and as a result theglass fibers are shortened significantly. The resultant mixture isformed into a molding material that is supplied to a press or injectionmolding system to be formed with very expensive tooling into GFRC parts.During the extrusion process using single or twin-screw machines, theresin is heated and melted and the fibers are dispersed throughout themolten resin to form a fiber/resin mixture. Next, the fiber/resinmixture may be degassed, cooled, and formed into pellets or slugs. Thedry fiber strand/resin dispersion pellets are then fed to a mouldingmachine and formed into moulded composite articles that have asubstantially homogeneous dispersion of glass fiber strands throughoutthe composite article. Alternatively, in the process using continuousfilaments, fiberglass filaments are mixed with the molten resin in anextruder with the screw geometry designed to mix the matrix with fiberswithout causing significant damage to the fibers. The resultant extrudedmixtures are then compression molded to form long-fiber reinforcedthermoplastic parts having superior mechanical properties due to thenature of the orientation and the longer length of the fibers. Becauseof these difficulties, the use of thermoplastics to make vehicle partswas limited.

With the newly proposed challenging CAFÉ gas mileage standards beingintroduced and growing needs for lighter weight parts in aircraft, thereis a greater need for lighter weight parts that thermoplastic fiberreinforced composite (TPFRC) could satisfy. The thermoplastic polymersor copolymers can be recycled by melting and reclaiming, and groundthermoplastic TPFRC can be used in thermoplastic forming processesincluding injection molding, extrusion, etc. Thus, there is a large needfor TPFRC parts using thermoset processes including RIM, SRIM, RTM,VARTM, reactive compounding, reactive injection molding including LFI,SMC, BMC, spray-up hand lay-up etc. if ways could be found to polymerizeand form the thermoplastic polymers, copolymers and homopolymers in situsurrounding the fiber reinforcements in a mold.

Low viscosity caprolactam monomers, one containing an activator andanother mixture containing a caprolactam monomer and a catalyst may becast by mixing the two very low viscosity mixtures together prior tocasting. However, this mixture often should be kept to less than about100° C. to prevent rapid polymerization. Following casting, the castmixture is heated in the mold to cause anionic polymerization of themonomer to produce a polyamide. However, this method is not practicalfor most vehicle and large parts and many other current thermoset partsbecause of the relatively low temperature limitation and the time delaysthat are caused in the forming and polymerizing cycle. If TPFRC is toreplace metals or thermoset fiber reinforced composites (TSFRC)substantially in the automotive industry and elsewhere, economicalmethod(s) need to be found that will produce such automotive parts ofequal or superior performance at competitive costs with metal and TSFRCparts now in use. This is achieved with the methods described herein.

BRIEF SUMMARY OF THE INVENTION

Processes used for making fiber and/or flake reinforced thermosetcomposites to be more easily used to make fiber reinforced and/or flakeand/or particle stabilized and/or colored laminates comprised ofthermoplastic cores or layers bonded to and/or surrounded by one or morethermoplastic layers and/or one or more thermoset layers, or for athermoset core or layer(s) to be bonded to and/or surrounded by one ormore thermoplastic layers and/or one or more thermoset layers aredescribed. In all such variations, at least one of the layers maycontain one or more of reactive fibers and/or reactive flakes and/orreactive particles. Reactive fibers/flakes/particles may includefibers/flakes/particles that have a residue on their surfaces thatcomprise one or more of a polymerization initiator (PI), a precursor ofa PI, a polymerization catalyst, or a precursor of such a catalyst. Theresidue on the surfaces of the fibers, flakes and particles may beproduced by coating the fibers, flakes and particles with a liquidsizing composition and then, when desired, drying the fibers, flakes andparticles to remove the liquid.

Present embodiments include methods of forming a multi-componentreinforced composite. The methods may include forming a firstparticle-reinforced component. The first particle-reinforced componentmay be formed by a process that includes providing reactive particlesthat have a reactive polymerization promoter chemically bonded or coatedon the surface of the reactive particles and contacting the reactiveparticles with a resin solution that includes monomers of a polymer. Thepolymerization promoter that is chemically bonded or coated on thesurface of the reactive particles may promote the polymerization of themonomers. The resin solution may subsequently be polymerized forming apolymer matrix around the reactive particles resulting in the formationof the first particle-reinforced component. A second polymer-containingcomponent may then be formed that is in contact with the firstparticle-reinforced component.

An alternative method of making a multi-component reinforced compositeincludes forming a first polymer-containing component and forming asecond particle-reinforced component that is in contact with the firstpolymer-containing component. The second particle-reinforced componentmay be formed by a process that includes providing reactive particlesthat have a reactive polymerization promoter chemically bonded or coatedon the surface of the reactive particles and contacting the reactiveparticles with a resin solution that includes monomers of a polymer. Thepolymerization promoter that is chemically bonded or coated on thesurface of the reactive particles may promote the polymerization of themonomers. The mixture of the reactive particles and the resin solutionmay then be introduced to the first polymer-containing component. Theresin solution may subsequently be polymerized forming a polymer matrixaround the reactive particles resulting in the formation of the secondparticle-reinforced component in contact with the firstpolymer-containing component.

The present methods include making a reinforced and/or stabilized and/orcolored laminate containing at least two layers, one of the layerscontaining one or more of reactive fibers, reactive flakes and reactiveparticles in composite parts and products. Reactive thermoplastic andthermoset materials may be used in reactive extrusion and/or reactiveinjection molding processes. The processes include resin transfermolding (RTM), reactive injection molding, injection pultrusion, and theuse of other systems that have and use a two-pot melting and injectionsystem. Additionally, a process may include the use of only one pot,except in instances where a two or more layered composite product isdesired. Existing two pot systems may be used to make two-layer ormulti-layer reinforced or unreinforced polymer laminates to improvestructural, aesthetic, and surface properties. The present methods alsopermit the use of only one pot on two pot systems, permit themanufacture of two pot systems to be simplified and cost reduced byincluding only one pot and substantially simplifies the above mentionedprocesses of forming reinforced polymer parts and products.

The present methods allow for the production, in these or slightlymodified forming systems, of laminates in which a strong, rigid,reinforced or unreinforced, stabilized and/or unstabilized and/orcolored or not colored, thermoset or am elastomeric thermoplasticpolymer layer, core layer or core can be protected by one or more layersof, sandwiched between two layers of, or surrounded by a layer of,tough, elastomeric reinforced or unreinforced, stabilized and/orun-stabilized and/or colored or not colored elastomeric thermoplasticpolymer, or a hard, rigid reinforced or unreinforced, stabilized and/orun-stabilized and/or colored or not colored thermoset polymer.

The present methods may include the use of polymer initiator(s) PI(s)and/or catalysts on the surfaces of the reinforcing fibers and flakes,and/or particles of fillers and/or pigments made reactive with the PI(s)and/or catalysts initiating polymerization of monomer(s) to producepolyamides, polyesters, polyurethanes and other polymers includingthermoplastic polymers whose monomers may be included in thepre-polymerized mixture include polybutylene terephthlalate (PBT),polyethylene terephthalate (PET), polyamide-6 (PA-6), polyamide-12(PA-12), polyamide-6,6 (PA-6,6), cyclic poly(1,4-butylene terephthalate)(CBT), polyurethanes (TPU), polymethylmethacrylate (PMMA),polycarbonates (PC), polyphenylenesulphide (PPS), polyethylenenapthalate(PEN), polybutylenenaphthalate (PBN), polyether etherketone (PEEK), andpolyetherketoneketone (PEKK), and combinations of two or more of thesepolymers, among other polymers commonly used. When polymerizing a PBTsystem the reactive fibers and/or flakes do not have a PI on theirsurfaces, only one or more catalysts for polymerization of PBT are ontheir surfaces. Not having to mix a catalyst with the PBT before formingis a valuable improvement due to the tendency for the PBT to polymerizeprematurely in present systems and processes.

The PI(s) can be coupled or non-coupled. The PI(s) for polyamide may beisocyanate-based or non-isocyanate-based. PBT to polyester systems maynot use a PI, and only a catalyst may be necessary on the surfaces ofthe fibers and flakes to polymerize the cyclic poly(1,4-butyleneterephthalate) (CBT) monomer to cyclic PBT. Suitable catalysts includetin-containing compounds and/or titanium-containing compounds. Forexample the catalysts may include organotin and/or organotitanatecompounds. Tin-containing compounds may include monoalkyltin(IV)hydroxide oxides, monoalkyltin(IV) chloride dihydroxides, dialkyltin(IV)oxides, bistrialkyltin(IV) oxides, monoalkyltin(V) tris-alkoxides,dialkyltin(IV) dialkoxides, and trialkyltin(IV) alkoxides, among othertin-containing compounds. Exemplary titanium-containing compoundsinclude titanate tetraalkoxide compounds (e.g., tetraisopropyl titanate)and tetraalkyl titanate compounds (e.g., tetra(2-ethylhexyl)titanate),among others.

For polyurethane, epoxy or other blocked isocyanates including blockingagents such as oximes such as methyl ethyl ketoxime, acetone oxime, andcyclohexanone oxime, lactams such as epsilon-caprolactam, and pyrazolesmay be used as PIs. Precursors thereof and isocyanates including blockedtrimethylene diisocyanate, blocked tetramethylene diisocyanate, blockedhexamethylene diisocyanate, blocked butylidene diisocyanate, blockedisophorone diisocyanate, blocked methyldiphenyl diisocyanate, blockedtoluene diisocyanate, blocked 1,4-cyclohexane diisocyanate, blockedhexamethylene diisocyanurate, blocked hexamethylene diisocyanate biuretand combinations thereof may also be used. The blocked-isocyanate PIs orthe precursors thereof may also comprise a silane end-group for couplingto the glass surface.

Reactive materials including fibers and/or flakes and/or fillerparticles and/or pigment particles may be used with thermosettingmaterials. The reactive materials described above may have one or morematerials on their surfaces that may, at the appropriate temperaturescause the thermosetting materials to polymerize to form reinforcedthermoset composites.

Present embodiments include the use of reactive reinforcing fibersand/or flakes and/or particles of fillers and or particles of pigmentssized with sizing compositions, the dried residue thereof, on theirsurfaces. Present embodiments also include fiber reinforcementsincluding glass fibers or flakes and particles of fillers and pigmentssized using sizing compositions containing one or more PI(s), precursorsthereof or catalyst(s) for causing polymerization of various monomers toform polymers including polyamide 6, polyester (PBT), polyurethanes andother polymers to size reinforcing fibers or flakes to produce reactivereinforcing fibers and flakes. When a heated monomer comes into contactwith the reactive reinforcing fibers and/or flakes, containing one ormore catalyst(s) or one or more PI(s), or precursor(s) thereof,polymerization begins and proceeds to form the polymer. With the presentembodiments it may not be necessary to put one or more PI(s) or one ormore catalyst(s) in separate monomer (i.e. two separate pots) to producecomposite parts in the above described processes. This may beaccomplished by placing one or more polymerization (PIs), or one or moreprecursors of such PI(s) onto the reinforcing fibers and/or flakes asone, or two separate coatings, and combining low viscosity thermoplasticmonomers including caprolactam, polybutelene terathylate (PBT) andothers, and optionally using mixtures of such monomer(s) containing oneor more catalysts, including butylchlorotin dihydroxide, tetraisopropyltitanate, tetramethylammonium tetraphenyl borate, compounds containingtertiary amines or quarternary ammonium salts, and organotin and/ororganotitanate compounds. Tin-containing compounds may includemonoalkyltin(IV) hydroxide oxides, monoalkyltin(IV) chloridedihydroxides, dialkyltin(IV) oxides, bistrialkyltin(IV) oxides,monoalkyltin(V) tris-alkoxides, dialkyltin(IV) dialkoxides, andtrialkyltin(IV) alkoxides, among other tin-containing compounds.Exemplary titanium-containing compounds include titanate tetraalkoxidecompounds (e.g., tetraisopropyl titanate) and tetraalkyl titanatecompounds (e.g., tetra(2-ethylhexyl)titanate), among others for PBT.Compounds represented as Y—(X)_(n)-A, where Y is either a couplingmoiety for bonding with the surfaces of the fibers and/or flakes, e.g.glass, A is ring-opening polymerization catalyst or initiator moietycapable of participating in a ring-opening polymerization of a monomerwhen exposed to ring-opening polymerization conditions, and X is alinking moiety capable of linking the Y moiety to the A moietychemically. The n is an integer ranging from zero to 3. When n is zero,the catalyzing moiety itself may be capable of coupling with thereinforcement surface. In additional embodiments, Y could also bereplaced with A, in which case it is not necessarily coupled to thereinforcement surface. Examples of initiators for polymerizingpolyamides include

N-hexamethyldiisocyanato-capped caprolactam, N-acetylcaprolactam,Isophthaloylbiscaprolactam, Isocyanatopropyltriethoxysilane-cappedcaprolactam and others including caprolactam esters such as benzoylcaprolactam, reaction products of acryloyl/methacrylol caprolactam withamino/mercapto silanes or non-silane amines/thiols, compounds/reactionschemes depicted by

where m is a integer with a value of 0 to 12, or any initiator depictedby

wherein

represents a C₃ to C₁₂ substituted or unsubstituted cyclic hydrocarbonchain.

Cyclized PBT oligomer is converted to linear PBT in the range of about180° C. to about 200° C. in the presence of a catalyst. The elevatedtemperatures for polymerization of the caprolactam monomers can beoptionally in the range of about 110° C. for a few minutes, up to about5-10 minutes to complete or complete sufficiently the reaction(s) toform the activator in situ, before raising the temperature to thefollowing higher levels. In alternative embodiments, the temperature mayinitially be about 140° C. to about 200° C., about 150° C. to about 180°C., or about 150° C. to about 170° C., to cause the anionicpolymerization of at least about 90 percent (for example, more than 97percent) of the monomer(s) resulting in a similar percentage ofpolycrystalline polyamide or other polymer.

Present embodiments of the methods include making reinforced thermosetcomposites such as laminates of all types including unsaturatedpolyesters, vinyl esters and acrylates that cure via free radicalpolymerization as one or more layers of the laminates. Reactive sizingon the surfaces of the reinforcing fibers and/or flakes may compriseeither one or more catalysts or one or more PI(s) physically orchemically bonded to the surfaces. The catalysts may include metalsalts, amines, thiols, acids and combinations thereof. Free radicalPI(s) include hydroperoxides.

Embodiments may include having one or more PI(s) present on the surfacesof the reinforcement fibers and/or flakes. Exemplary fibers and/orflakes include glass, such as E glass, however a broad range ofmaterials suitable for the reinforcement fibers and/or flakes may beused. In some of the embodiments one or more catalysts may also bepresent in the sizing composition and on the surfaces of the reinforcingfibers and/or flakes. The present sizing compositions may include aliquid and either one or more PI(s) or one or more precursors of suchone or more PI(s) either in a single coating or in two or more coatings.The present sizing compositions may also be used in methods of makingreactive reinforcements.

The present methods simplify the RTM, RIM, VARTM/RIM, (vacuum assistedRTM or RIM), pultrusion, injection molding and filament winding systemsand processes by placing the PA and/or catalyst on the surface of thereinforcement fibers and/or flakes. For example, the cost and addedcomplexity of the equipment needed, such as additional resin tanks,heaters, pumps, lines, valves, mixers, etc., and the elimination of suchequipment means that the maintenance costs including cleaning andmixing, are substantially reduced. Where the complex systems currentlyexist, the present embodiments free up one or more monomer or monomermixture portion of the system to permit the molding system to makelaminate or over-molded parts and/or products by using the first shot tomake a Nylon 6 or PBT core or layer and then at the appropriate time,having used the other monomer or monomer mixture equipment to make asecond shot of polyurethane or PBT to produce a outer surface or secondlayer having enhanced properties including one or more of moistureabsorption, smoothness, hardness level, etc. In other embodiments, astrong thermoset core can be over-molded with a more impact resistant,tougher thermoplastic shell.

Optionally, all of the fiber and/or flake, and the reactive filler(s)and/or pigment(s) and the monomer or monomer mixture may be preheated toor near the desired polymerization temperature. When molds are involvedthe molds may also be preheated at least above the melting point of themonomer when the monomer is solid at room temperature. After forming,the composite, in or out of the mold, may be placed in a hot environmentto complete the polymerization to the desired degree. The totalpolymerization time will depend upon the temperature and degree ofpolymerization. For example, the polymerization reaction may take about5 to about 15 minutes which may or may not include the up to about 10minutes if the one or more polymerization activators are formed in situon the fibers in the initial stage of impregnating the reinforcingfibers with the one or more monomers. In the latter case, if more timeis needed to complete polymerization at the higher temperatures, anotherfew minutes up to about 10 minutes may be taken because during thisamount of time the reinforcements and mold temperature will be held atabout 120° C. to first form the activator(s) before raising thetemperature to the higher, polymerization temperatures.

Present embodiments also include methods of making reinforced polyamide6 and/or PBT molding slugs or pellets for molding, and reinforcedpolyamide 6 and/or PBT composite parts in processes including RIM,VARIM, SRIM, pultrusion, filament winding and high pressure injectionmolding. In these methods two separate melting vessels may be used withone melting vessel melting a mixture of lactam monomer and one or morecatalysts at 80° C.-160° C. and the other melting vessel melting amixture of cyclic poly(1,4butylene terephthalate monomer and one or morecatalysts at 150° C.-160° C. These two melts may then be directed inseparate pipes into mixing head where they are mixed thoroughly and thendirected in a one or more pipes to a heated mold, the mold containing afibrous preform, previously made from chopped fibers, rovings, nonwovenmat(s) or woven fabric(s). To reduce molding time, the preforms may bepreheated to a temperature in the range of about 100° C. to about 220°C. before placing the preform into the heated mold. The mixed monomer,PI(s) and catalyst(s) impregnate the fibrous preform surrounding thefibers and polymerize due to the heat of the mold and preform at about160° C.-180° C. for polyamide 6 and 170° C.-210° C. for PBT, formingfiber reinforced polymide 6 composite. The amount of reinforcing fiberin these composites may be in the range of about 30 to about 80 wt.percent.

Some embodiments include methods that are a variation of the justdescribed methods. The variation involves first sizing or coating thefibers with a sizing composition that includes one or more PI(s) for thecaprolactam and PBT and then either chopping and drying the fibers orwinding and drying the fibers before they are used to make the fibrousperforms. The sizing compositions may be solvent based and may usesolvents such as water as the liquid carrier, and may also contain oneor more catalysts for the polymerization of caprolactam and/or PBT plusoptionally other fiber sizing ingredients. For example, the sizingcompositions may optionally contain one or more organo-silane couplingagents, optionally one or more lubricants to protect the fiber surfacefrom scratching, gouging, etc. and can optionally contain one or morefilm formers for coating the fiber and bonding the other non-wateringredients to the surfaces of the fibers. The size may also containenough PI to polymerize the mixture of monomer and catalyst that may beforced into the heated mold and heated fibrous perform. In thisalternative method of making fiber reinforced polyamide 6 composites,only one melting vessel may be used to melt the mixture of caprolactamand the one or more catalysts and this melted mixture may either gostraight to the mold, or optionally may pass through a mixing head forbetter homogeneity.

As an alternative to the embodiments described just above, furtherembodiments include a sizing that contains a silane chemically bonded toa one or more PI(s) instead of the PI(s) and the optional organo-silanecoupling agent being separate compounds. In these embodiments, thesilane is chemically bonded to the fibers, particularly to fiberscontaining silica or a compound containing silica, and the PI willbecome bonded, for example, chemically bonded, to the polymer matrixproviding for greater interfacial strength between the reinforcingfibers and the polymide 6 and/or PBT polymer matrix.

Further embodiments include a sizing that contains one or moreprecursors for the PI(s) and/or the catalyst(s). Where more than oneprecursor is used, one or more precursors may be present in the sizecomposition, or one or more precursors may be present in a first sizecomposition and the other precursor(s) may be present in a second sizecomposition applied after the first size composition is applied with orwithout a drying step between the sizing applications. These sizes mayalso be applied to fibrous webs in the wet, nonwoven mat formingprocesses and the and dry, nonwoven mat forming processes disclosedearlier, and also to the woven fabric, all followed by drying.

An additional method of applying the sizing containing thepolymerization initiator(s) to the reinforcing fibers includes asecondary fiber and/or flake, filler and pigment coating application.This secondary coating application may be prior to the fibers beingchopped or wound, after the fibers are dried followed by another dryingstep, or when the fibers are used to make a nonwoven mat, nonwoven orwoven scrim or woven fabric, the sizing may be impregnated into the mat,scrim or fabric or onto the flakes by spraying or passing a excess ofsizing onto the mat, scrim or fabric with the excess passing through themat, scrim or fabric to be collected and reused. In the case where thenonwoven mat is made by a wet process, the sizing can be applied, aloneor in a binder mixture, to the wet web, of fibers before drying thesized mat, and curing the binder if present. Where the mat is formed bya dry process the initiator sizing can be applied to the dry web, aloneor in a binder mixture, followed by drying the mat, and curing thebinder, if present.

Where the fiber preforms are made to shape by a wet process, the sizingcontaining the PI(s) may be in the water of the slurry, or may besprayed onto the perform in excess after the wet perform has been formedand the excess sucked through the perform as in the mat, scrim andfabric application. Where the perform is made by hand lay-up orspray-up, the sizing containing the PI(s) with or without a binder, maybe sprayed onto the collected chopped fibers, strands or rovings as thethickness of the perform is being built up.

Flakes, usually glass flakes, when used in the present embodiments maybe prepared by spraying the size composition onto the flakes while theflakes are stirred in a mixer that does not significantly degrade theflakes, to disperse the size over the surfaces of the flakes followed bydrying the sized flakes. This process may be repeated with a differentsizing containing a catalyst or a precursor of either the PI(s) or thecatalyst producing dry flakes having two layers of sizing coating theflakes. The reinforcing fibers used for making reinforced composites mayinclude glass fibers, any of the glass types used for reinforcingpolymers, and E glass. The reinforcing fibers need not be glass, nor doall of the fibers need to be glass. Other reinforcing fibers useful inplace of all, or a portion of the glass fibers include, slag fibers,carbon fibers, ceramic fibers, alumina fibers, silica fibers, rockfibers including basalt fibers, asbestos, wollastinite fibers, fibroustalc, metal fibers and polymer fibers including fibers of aramid,polyester and polyethylene. Additionally, any combination of thesefibers may be used. Reactive fillers and/or pigments may also be used inplace of or in addition to the reactive fibers and/or flakes, and withnon-reactive fibers and/or non-reactive flakes. The fibers, flakes,filler particles and pigment particles may be of any material used toreinforce, stabilize and/or color and/or to texture thermoplastic andthermoset composite parts or products.

Herein, when a range of number values is disclosed it is to beunderstood by those of ordinary skill in the appropriate art(s) thateach numerical value in between the upper limit and the lower limit ofthe range is also disclosed, to at least 0.01 of a full number. Thus ina range of 1 to 10, this includes 2.04 to 10, 3.06 to 8 or 8.50, and soon. The addition of a new limitation in a claim previously stating from2 to 7 changing it to from 3-7 or 4-6 would not introduce new matterwhether those new ranges were specifically disclosed in thespecification or not because of this explanation of the meaning of adisclosed broader range, such as 1-10. This meaning of a range is inkeeping with the requirement in 35 USC 112 that the disclosure beconcise.

Further, when the word “about” is used herein it is meant that theamount or condition it modifies can vary some beyond that stated so longas the advantages of the invention are realized. Practically, there israrely the time or resources available to very precisely determine thelimits of all the parameters of one's invention because to do so wouldrequire an effort far greater than can be justified at the time theinvention is being developed to a commercial reality. The skilledartisan understands this and expects that the disclosed results of theinvention might extend, at least somewhat, beyond one or more of thelimits disclosed. Later, having the benefit of the inventors' disclosureand understanding the inventive concept and embodiments disclosedincluding the best mode known to the inventor, the inventor and otherscan, without inventive effort, explore beyond the limits disclosed todetermine if the invention is realized beyond those limits and, whenembodiments are found to be without any unexpected characteristics,those embodiments are within the meaning of the term “about” as usedherein. It is not difficult for the artisan or others to determinewhether such an embodiment is either as expected or, because of either abreak in the continuity of results or one or more features that aresignificantly better than reported by the inventor, is surprising andthus an unobvious teaching leading to a further advance in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic drawing of a continuous glass fibermanufacturing system for making wound, reinforcing fiber productsaccording to embodiments of the invention.

FIG. 2 is a simplified schematic drawing of a system for making desiredlengths of chopped reinforcing fibers and fiber strands according toembodiments of the invention.

FIG. 3 is a simplified schematic drawing of a system for applying asecond size composition to fibers or fiber strands according toembodiments of the invention.

FIG. 4 is a simplified schematic drawing of a system for making anonwoven mat and applying a sizing to fibers in the nonwoven mataccording to embodiments of the invention.

FIG. 5 is a simplified schematic drawing of a portion of a nonwoven matsystem showing an additional system for applying a one or more sizingsto a nonwoven fiber mat or to a woven fabric according to embodiments ofthe invention.

FIG. 6 is a simplified schematic drawing of a modified pultrusion systemaccording to embodiments of the invention.

FIG. 7 is a simplified schematic drawing of a modified filament windingsystem according to embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Present methods may use PI(s) such as caprolactam, polybuteleneterathylate (PBT) and others, and may optionally use mixtures of suchmonomer(s) containing one or more catalysts, including butylchlorotindihydroxide, tetraisopropyl titanate, tetramethylammonium tetraphenylborate, compounds containing tertiary amines or quarternary ammoniumsalts, and organotin and/or organotitanate compounds. Tin-containingcompounds may include monoalkyltin(IV) hydroxide oxides,monoalkyltin(IV) chloride dihydroxides, dialkyltin(IV) oxides,bistrialkyltin(IV) oxides, monoalkyltin(V) tris-alkoxides,dialkyltin(IV) dialkoxides, and trialkyltin(IV) alkoxides, among othertin-containing compounds. Exemplary titanium-containing compoundsinclude titanate tetraalkoxide compounds (e.g., tetraisopropyl titanate)and tetraalkyl titanate compounds (e.g., tetra(2-ethylhexyl)titanate),among others. Compounds represented as Y—(X)_(n)-A, where Y is either acoupling moiety for bonding with the surfaces of the fibers and/orflakes, e.g. glass, A represents ring-opening polymerization catalyst ora PI(s) moiety capable of participating in a ring-opening polymerizationof a monomer when exposed to ring-opening polymerization conditions, andX is a linking moiety capable of linking the Y moiety to the A moietychemically. The n is an integer ranging from zero to 3. When n is zero,then the catalyzing moiety itself is capable of coupling with thereinforcement surface. In another version of this compound, Y could alsobe replaced with A, in which case it is not necessarily coupled to thereinforcement surface. Examples of PI(s) for polymerizing polyamidesinclude N-hexamethyldiisocyanato-capped caprolactam,N-acetylcaprolactam, Isophthaloylbiscaprolactam,Isocyanatopropyltriethoxysilane-capped caprolactam and others includingN-acyllactams, caprolactam esters and lactam-blocked isocyanates presentin a range of about 0.5 to about 5 wt. percent of the monomer. Usingthese polymerizing caprolactam systems results in fast polymerizationreaction kinetics, clean polymerization without any by products and acrystalline polyamide 6 polymer.

Cross-linking and branching issues in the polymerization of Nylon 6,polyamide 6, may be avoided by the use of non-isocyanate polymerizationinitiators such as acyllactams in combination with a Grignard salt ofcaprolactam as a catalyst. Using such a system results in a rapidpolymerization reaction kinetics, clean polymerization without any byproducts and a crystalline polyamide 6 polymer. An example of such asystem is the use of N-acetyl caprolactam as the initiator

Grignard salt of lactam may be useful as a catalyst. A Grignard salt ofa lactam may be safely made in one reaction operation by reacting ametal Mg with an alkyl halide or an aryl halide and a lactam. A lactamshown by the formula I (R is 3-11C aliphatic hydrocarbon residue) isreacted with metal Mg and an alkyl halide or an aryl halide at −15-120°C., to give a compound shown by the formula II (n is 3-11; Y is Cl, Br,or I). Metal Mg having a small amount of oxidized film on the surfaceand >/=90% purity may be used as the metal Mg, and it may be in the formof a flake, powder, etc. having large specific surface area. Amonohalogenated hydrocarbon may be used as the halogenated hydrocarbon,and the amount used may be 1.0-1.5 mol based on 1 mol metal Mg. Anamount of the lactam used may be 0.9-5 mol based on 1 mol metal Mg.

Chemical sizings applied to the surfaces of the fibers, including glassfibers and/or glass flakes and other fibers containing silica and/oralumina, may contain a lubricant, a film former and a silane couplingcompound. The lubricant protects the surface of the fibers, which isessential to maximize the strength of the fibers and protect the fibersfrom scratches, etc. caused by fiber-to-fiber rubbing abrasion andprocessing equipment. The silane acts as the chemical linking agent bybonding to the glass fiber and also to the polymer/copolymer matrix.Silanes containing organosilane groups may be used as coupling agentsfor glass fibers and organic (e.g. polymer) phase, and serve tocovalently bond the organic groups in the compound to groups on theinorganic surfaces. The film former provides the desired degree of bondbetween the fibers in the fiber strands to avoid fuzzing and excessfilamentation during processing in the fiber manufacturers operationsand/or in the composite manufacturers' operations. The sizing may alsocontain one or more ring-opening or PBT polymerization catalystscompounds, or one or more precursors thereof, and, in some embodiments,a linking compound capable of linking the silane compound and thePI/catalyst compound(s) or precursor(s) together and to the surfaces ofthe reinforcement(s). Examples of linking compounds may includecompounds containing a covalent bond, an alkyl group, an aryl group, analkene group, an amine group, or a thiol group among other linkingmoieties that may cause polymerization of the hot monomer mixture toform a polymer matrix around and bonded to the reinforcing glass fibers.Sizings may be applied to flakes by spraying onto the flakes in a fluidbed or mixer followed by drying.

The chemical sizing compositions include a liquid carrier such as water,and either one or more PI(s) or one or more precursors of one or morePI(s) and may also optionally contain one or more other functionalingredients. The sizing may contain one or more silane coupling agents,one or more lubricants to protect the surfaces of the fibers fromdamage, and one or more surfactants or wetting agents, etc. and may alsooptionally contain one or more resinous film formers for bonding theother ingredients to the fibers and also to provide a bond of desiredstrength between the many fibers in a strand formed by a plurality offibers from the bushing 2.

The present embodiments may be applicable to a broad range of sizingcompositions so long as each contains at least one PI or one catalystfor polymerization of either PBT or of polyamide 6 or at least oneprecursor for the at least one such PI or catalyst.

The sizing may include one or more coupling agents for chemicallybonding the fiber to the polymer matrix chemically. Suitable couplingagents include aminosilanes, the reaction product of an aminosilane,maleic anhydride, ureidosilanes, vinylsilanes, and blends thereof. Anexemplary silane is A1100, available from OSI Specialties. This productcontains 52% by weight active silane solids following hydrolysis.Another exemplary silane that may be used is a hydrolyzed A1100 solutionin water, also available from OSI Specialties under the designationVS142 (40% solution) or from Huils under the designation A1151 (40%solution). In an embodiment where one or more of the PI(s) or precursorsare silanes, the majority of the coupling between the organic moleculesand glass is effected by the PI(s) or the precursors. Additionalcoupling silanes may also be used.

The size compositions may contain one or more surface modifying orcoupling agents selected from functional organo silane, organo titanateand organo zirconate coupling agents. The amount of functionalorgano-silane coupling agent may be about 1 to about 30 wt. percent,about 4 to about 20 wt. percent, or about 6 to about 12 wt. percent ofthe forming size composition on a total solids basis.

The size compositions may contain one or more lubricants, to protect thesurfaces of the fibers and flakes and to aid manufacturing reducingfriction where the wet fibers slide past, on or over guides and otherphysical objects. A small amount, usually no more than about 0.15 weightpercent of the size composition of a lubricant compatible with theliquid in the sizing may be used. Suitable lubricants for this purposeinclude one or more of the following: a nonionic surfactant such as ablock copolymer of ethylene oxide and propylene oxide, e.g. LUVISKOL Kgrade and PLURONIC L101 (available from BASF of Florham Park, N.J.) orSYNPERONIC PE/IL101 (available from AkzoNobel of Morris, Ill.),polyethyleneimine polyamide salt, such as EMERY 6760 (available fromHenkel Corp. of Rocky Hill, Conn.); octylphenoxypolyethoxyethanol suchas TRITON X100 (available from Rohm and Haas of Philadelphia, Pa.); apolyvinyl pyrrolidone, e.g., an imidazoline, e.g., an alkylimidazolinederivative such as TEGO cationic softener (available from Th.Goldschmidt AG of Essen, Germany), amine salts of fatty acids, e.g.,including a fatty acid moiety having 12 to 22 carbon atoms and/ortertiary amines having alkyl groups of 1 to 22 atoms attached to thenitrogen atom), alkyl imidazoline derivatives (can be formed by thereaction of fatty acids with polyalkylene polyamines), acid solubilizedfatty acid amides (e.g., saturated or unsaturated fatty acid amideshaving acid groups of 4 to 24 carbon atoms such as stearic amide), acidsolubilized polyunsaturated fatty acid amides, condensates of a fattyacid and polyethylene imine and amide substituted polyethylene imines,such as EMERY 6717, a partially amidated polyethylene imine commerciallyavailable from Henkel Corporation of Kankakee, Ill. and ALUBRASPIN 226,available from PPG Industries, Inc. of Pittsburgh, Pa., alkylimidazoline derivatives including CATION X, available from GoldschmidtChemical Corporation (see above), and ALUBRASPIN 261, available from PPGIndustries, Inc. (see above), and cationic lubricants such as silylatedpolyamine polymers prepared by reacting: (a) an amino functionalreaction product of an aminofunctional polymer having primary orsecondary amine functionality and the residue of a fatty acid moiety;and (b) an amine-reactable organo alkoxy silane and hydrolysis productsthereof. Other lubricants include Emerset 2646 and Emerset 2661,available from Emery Industries of Waterloo, Iowa. When one or morelubricants are used in the sizing compositions the total amount of theone or more lubricants in the size composition may be about 0.1 to about10 weight percent, about 0.5 to about 5 weight percent, or about 1 toabout 3 weight percent of the forming size composition on a total solidsbasis.

The size compositions may optionally include a film former forphysically bonding the PI(s), PI precursor(s), catalyst(s) or catalystprecursor(s) to the fibers and flakes. Many film formers may be usedincluding FULATEX PD-0166 and FULATEX PN-6019, both available fromFuller. FULATEX PN-6019 is a modified vinyl acetate copolymer in ananionic/nonionic surfactant system having a solids content of 53.5 to55.5 weight percent; a pH of 3.5 to 4.5; VINAMUL™ 88127 or N.S. 25-1971available from National Starch of Bridgewater, N.J. is a copolymercontaining from about 53.5 to 55.5 weight percent solids, and having apH of 4 to 5; FULATEX PD-0166 and FULATEX PN-6019, which are bothavailable from the H. B. Fuller Company of St. Paul, Minn. FULATEXPN-6019 is a modified vinyl acetate copolymer in an anionic/nonionicsurfactant system with the following properties: solids content of 53.5to 55.5 weight %, viscosity of 100 to 600 cps, pH of 3.5 to 4.5, and aresidual monomer content of 0.5% or below. Another film former that maybe used is VINAMUL™ 88127 which is available from Vinamul U.K. or fromNational Starch under the product code N.S. 25-1971. This copolymer maycontain from 53.5 to 55.5% by weight solids, has a pH of 4 to 5, and aviscosity of from 100 to 400 mPa·s. The film-forming material may alsobe one or more N-vinyl amide polymers prepared from a cyclic monomer,for example N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone,N-vinyl-.epsilon.-caprolactam, N-vinyl-5-methyl-2-pyrrolidone,N-vinyl-3,3,5-trimethyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone,isomers, derivatives and mixtures thereof. Epoxy film formers such asNeoxil™ 965, available from DSM Composite Resins AG of Schaffhausen,Switzerland are suitable as are polyurethane-based film formersincluding Hydrosize™ U1-01/U6-01 available from Hydrosize Technologies,Inc. of Raleigh, N.C. When one or more film formers are present in thesize compositions the total amount of film former present may be about0.5 to about 15 wt. percent, about 1 to about 10 wt. percent, or about 1to about 5 wt. percent of the forming size composition on a total solidsbasis.

The size compositions may also optionally contain one or more ofemulsifying agents, surfactants, plasticizers, film former modifiers,biocides and other size composition functional aids. The size may alsoinclude a pH adjusting agent, such as an acid or a base, in an amountsufficient to achieve a desired pH, for example, a pH of about 6 toabout 8.5. Exemplary acids include acetic, citric, sulfuric, phosphoricand similar acids. Exemplary bases include ammonium hydroxide andpotassium hydroxide. Each size composition may be applied to the fibersand flakes and then dried with the dried solids of the size beingpresent on the fibers and flakes in an amount in the range of about 0.1to about 5 wt. percent, based on the weight of the dry fibers andflakes. Additional ranges may include about 0.5 wt. percent to about 3wt. percent and about 1 wt. percent to about 2 wt. percent, measured bya loss on ignition (LOI) test of the fiber or flake products.

When one or more PI(s) are present in the sizing composition the amountof total PI solids in the sizing may be in the range of about 2 wt.percent, dry basis, to about 30 wt. percent. Exemplary ranges mayinclude about 5 wt. percent to about 20 wt. and about 8 wt. percent toabout 16 wt. percent. When one or more catalysts are present in thesizing, the amount may be in the range of about 2 wt. percent to about20 wt. percent, dry basis. Exemplary ranges include about 5 wt. percentto about 15 wt. percent and about 8 wt. percent to about 12 wt. percent.As a further guide, below are a few of many possible sizingcompositions.

SIZE COMPOSITION # 1: Ingredient Weight % Caprolactam silane^(a) 12 Filmformer^(b) 1.2 Lubricant^(c) 1.1 Acetic Acid 0.03 Ammonium Hydroxide0.04 Deinoized water 85.63 ^(a)Choice of silanes such as reactionproduct of acryloyl caprolactam + aminopropyltriethoxysilane or acryloylcaprolactam + mercaptopropyltrimethoxysilane or methacryloylcaprolactam + amino/mercaptosilane or any other trialkoxysilanecontaining end group specified by

wherein

represents a C3 to C12 substituted or unsubstituted cyclic hydrocarbonchain. ^(b)Choice of film formers such as Neoxil 965, HydrosideU-101/201/601 or any other Epoxy or PU-based film formers^(c)Combination of one or more lubricants from Emerest 2646, Emerest2661 and Emery 6717.Procedure

-   -   1. Add film former to ⅔ of deinoized water and stir in a mixing        tank    -   2. Add caprolactam silane and continue stirring    -   3. Add acetic acid as necessary and continue stirring for an        adequate period of time to ensure hydrolysis of silane (30        minutes-4 hours)    -   4. Add lubricants and mix for 5 minutes    -   5. Add rest of the DI water    -   6. Add ammonium hydroxide as necessary to ensure that the target        pH (7-8.5) is achieved without affecting the sizing stability    -   7. Record solids % and pH

SIZE COMPOSITION # 2 Ingredient Weight % Initiator for AP Nylon¹ 11Caprolactam silane^(a) 1 Film former^(b) 4 Lubricant^(c) 2 Acetic Acid0.01 Ammonium Hydroxide 0.01 Deinoized water 81.98 ¹Choice of initiatorsfrom acetyl caprolactam, isophthaloylbiscaprolactam, acryloylcaprolactam, methacryoyl caprolactam, benzoyl caprolactam, or any otherinitiator containing the end group specified by

wherein

represents a C3 to C12 substituted or unsubstituted cyclic hydrocarbonchain. ^(a)Choice of silanes such as reaction product of acryloylcaprolactam + aminopropyltriethoxysilane or acryloyl caprolactam +mercaptopropyltrimethoxysilane or methacryloyl caprolactam +amino/mercaptosilane or any other trialkoxysilane containing end groupspecified by

wherein

represents a C3 to C12 substituted or unsubstituted cyclic hydrocarbonchain. ^(b)Choice of film formers such as Neoxil 965, HydrosideU-101/201/601 or any other Epoxy or PU-based film formers^(c)Combination of one or more lubricants from Emerest 2646, Emerest2661 and Emery 6717.Procedure—Similar procedure as Example 1 may be followed for liquidinitiators wherein the initiator is added along with caprolactam silane.For solid initiators, the film former and water mixture is heated to 90°C. and the initiator is melted first before adding to the filmformer-water mixture. The contents are mixed well to ensure theformation of a stable dispersion of the initiator in water. The silaneis then added and the rest of the procedure is followed as per Example1.

SIZE COMPOSITION #3: Ingredient Weight % Precursor for initiator for APNylon² 8 Aminopropyltriethoxysilane* 1 Film former^(b) 3 Lubricant^(c) 2Acetic Acid 0.01 Ammonium Hydroxide 0.01 Deinoized water 85.98 ²Chosenfrom a group comprising of aminopropyltriethoxysilane,mercaptoproyltrimethoxysilane, acryloyl/methacryloyl caprolactam, ethylbenzoate or any other precursor molecules that in a secondary step reactwith another molecule such as caprolactam or others to produce aninitiator on the surface of the glass. ^(a)No additional silane isnecessary if the precursor is a silane. ^(b)Choice of film formers suchas Neoxil 965, Hydroside U-101/201/601 or any other Epoxy or PU-basedfilm formers. ^(c)Combination of one or more lubricants from Emerest2646, Emerest 2661 and Emery 6717.Procedure—The procedure as disclosed in Example 2 is used. Ifaminopropyltriethoxysilane is used, the hydrolysis is rapid and aceticacid is not necessary.

The reinforcing fibers and/or flakes that may be used include any typeof fiber product used to reinforce natural or organic polymers includingchopped fiber strands or pellets (agglomerates), chopped fiber rovings,chopped strands from wound cakes and assembled rovings, gun roving,chopped or long slivers, nonwoven fibrous mats and woven fiber fabrics.The reinforcing fibers may be of any length. For example, thereinforcing fibers may be at least 0.06 inches long up to lengthsexceeding 100 feet. The reinforcing fibers may be dry, but they may alsocontain up to about 0.5 wt. percent moisture or solvent. For example,the reinforcing fibers may contain less than 0.3 wt. percent moisture,less than 0.2 wt. percent moisture, or less than 0.1 wt. percentmoisture.

In many of the present embodiments, sized fibers and/or flakes are madeand used as reinforcements in polymers formed in situ around the sizedreinforcement fibers and/or flakes. One system and method useful inmaking the sized reinforcing fibers in a wound form is shown in FIG. 1.Fibers 1, including glass or polymer fibers, are formed by passing amolten form of the glass or polymer, etc. through orifices or nozzles onthe bottom of a refractory metal bushing 2 heated to the fiberizationtemperature of the material being fiberized, and the fibers 4 are pulledrapidly downward at speeds exceeding 500-1000 ft./min. to more than10,000 ft./min to attenuate the fibers to the desired diameter and toquickly cool the fibers 4 with air to below their softening point. Afine mist of water or other cooling fluid is sprayed onto the fibers tohelp cool them. and the fibers 2 are then pulled into contact with achemical sizing applicator such as a roller of a chemical sizingapplicator 5 where the surfaces of the fibers are coated with one of thechemical sizings of the present embodiments, or another chemical sizing.The chemical sizings may be water based, but other liquids may be usedin place of water including organic solvents including ketones, alcoholsincluding ethanol, methanol, esters or others, molten caprolactam withor without an aqueous medium or a combination of water and organicsolvents.

The chemically coated, wet fibers are next pulled into contact with agrooved pulley 7 that gathers all of the fibers 4 from the bushing 2into one or more strands 9. A second grooved pulley 8, either offsetfrom the first grooved pulley 7, or with the strand(s) 9 passing on anopposite side of the pulley 8, or both to provide some additional strandtension for a winder 10 located on the floor of the forming room belowand offset from bushing 2. The fiber strands 9 may contain any number offibers from a few hundred to more than 6000.

In systems for making continuous, wound sized fibers or sized fiberstrands, the fibers 4 and the fiber strands 9 may be pulled at thedesired speed by a winder, such as the roving winder 10 having arotating spindle 11 and a removable sleeve 12 on which to wind a rovingpackage 13 having square ends 14 and a relatively smooth outer diameter15 of a desired size. Following completion of the roving package 13, theroving winder 10 indexes to place another rotating mandrel 11 into placecontaining a fresh sleeve 12 and the strand(s) 9, are transferredmanually or automatically to the fresh sleeve to make another rovingpackage 13 without disrupting the pulling of the strand(s) 9. Instead ofa roving winder, a different type of winder for winding cakes, bobbinsor other package shapes may be used in this system. After the wetpackages, etc. are removed from the winder they are dried to remove allor most of the liquid carrier, to complete any coupling reaction(s) andto cure any film former in the sizing. The dried rovings or yarns arethen processed to make the reinforcing fiber and reinforcing roving andyarn products to be used to weave fabrics, to chop or to use to makefiber reinforced polymer composite products and parts.

Other reinforcing fiber products used to make reinforced composite partsor products include wet and dry chopped sized fibers and wet and drychopped fiber strands. FIG. 2 shows a system used to manufacture wet ordry chopped, sized fibers and fiber strands, or optionally agglomeratedwet and dry chopped sized fibers and sized chopped fiber strandproducts. In FIG. 2, different system portions are labeled as A, B, C, Dand E. Portion A is the fiber forming part of the system and may be thesame as the fiber forming system shown in FIG. 1, except that in thissystem the fibers or strands of fibers 9 are pulled around gatheringwheels 7 moving away from the turning wheels 7 in a generally horizontalorientation towards a chopper 16. Portion B is a chopper 16 forseparating fibers and fiber strands 9 into lengths 19 of about 0.06 inchup to 5 inches long or longer with exemplary lengths being 0.125 inches,0.25 inches, 0.5 inches, 0.75 inches, 1 inch, 1.25 inches, 1.5 inches,etc. The chopper 16 shown in FIG. 2 includes a guide roll 17, a backuproll 20 with a pulling roll 19 running against it and fibers or fiberstrands 9 on the surface of the backup roll. A blade or cutter roll 21set to cause a plurality of blades mounted in the blade roll 21 to pushagainst the fibers or fiber strands 9 on an elastomeric surface of thebackup roll 20, penetrating the elastomeric surface to some depthresults in producing the desired lengths of wet, sized fibers or fiberstrands 9. Other components include elements for starting a new fiber ora new fiber strand into the chopper 16 without interrupting the runningfibers or fiber strands 9 and may include an accelerating roll 22, asensor 22A to start the accelerator roll and a strand manipulator 18 topull the new strand into the nip between backup roll 20 and the pullingroll 19 once the new fiber or fiber strand is running at a desiredspeed.

The chopped fibers and/or fiber strands 19 may be collected on aconveyor belt or vibrating conveyor and may be either packaged wet, usedwet close by, or further processed. Portion D is a drying part of thesystem. One option is to feed the wet, chopped fibers into a dryer likea vibrating fluid bed dryer 28, mounted on a plurality of springs 32 andequipped with one or more vibrators 30. The wet, chopped fibers and/orfiber strands are fed onto a perforated bed having holes therein of asize such that the fibers and/or fiber strands will not fall through,especially as hot air is flowing upward through the holes and into thevibrating, often suspended layer of chopped fibers and/or fiber strandsto remove the liquid carrier, complete any coupling reaction(s) and tocure any film former that is on the surface of the fibers. The hot,moist air is exhausted through a stack 35 and a top cover 36 containsthe fibers and fiber strands in the dryer 28.

Portion E is an optional sorting and packaging portion of the system.The hot, dry chopped fibers and/or fiber strands 48 may optionally flowinto and through a size sorter 40 containing two or more screens 41 and42 to remove any oversize and under size (fuzz) material from thedesired product, discarding the material removed through a chute 44, andto cool the chopped, reinforcing fibers and/or fiber strands beforebeing packaged in packages 45.

Portion C of the system is optional. When it is desired to producepellets or agglomerates of the chopped fibers and/or fiber strands 19,the latter are fed into an optional agglomerator/pelletizer 24 that willagglomerate a plurality of the chopped fibers and/or fiber strands 19into separate pellets or football shaped agglomerates and densify thepellets and/or football shaped agglomerates 26 before feeding them intothe dryer 28. Optionally, the densified pellets and/or football shapedagglomerates 26 may be packaged wet for shipment or use on the premises.

Some of the sized, reinforcing fibers and/or fiber strands of thepresent embodiments, particularly those using two or more precursors forthe-PI(s) may use a two step sizing application using different sizecompositions in the two sizing steps. One system for use along with asystem for making first sized fibers, including the systems shown inFIGS. 1 and 2, for making such dual sized fibers and/or fiber strands isshown in FIG. 3. Here wet, sized fibers 9 sized with a sizingcomposition such as those coming from the systems shown in FIGS. 1 and2, are gathered and turned with the turning roll 7 rotatable on an axle54, then optionally onto a second roll 58 rotatable on an axle 60 andthrough a dryer 61 to optionally remove at least some of the liquid ofthe first sizing, and/or to gel the first sizing, and then onto otherrollers 64 submerged in a different sizing in a container 62. Thefiber(s) and/or fiber strands 65 coated with the second sizingcomposition are pulled from the container 62 by either a winder or achopper 67. From that point the wound or chopped sized fibers may beused, packaged wet or palletized, agglomerated and used or packaged ordried, optionally sorted, and packaged as described above in thedescription of FIGS. 1 and 2.

Other reinforcing fiber products include fibrous nonwoven mats and wovenfiber fabrics using either the sized reinforcing fibers made in thesystems disclosed above, or other reinforcing fibers that are sized withthe present sizing compositions during manufacture of the nonwoven matsand fabrics. Weaving systems may be used to weave fabrics and either wetor dry mat forming systems may be used to make the fibrous, reinforcingnonwoven mats. Dry systems may include chopped strand mat systems andcontinuous fiber strand mat systems. These and other dry forming matsystems may be used.

FIG. 4 is a schematic of a wet former system for making multi-layernonwoven mats except that it contains an optional second stockpreparation system. Sized fibers, or other reinforcing fibers and/orfiber strands, particulate or both 105 are fed, for example,continuously, but batch type preparation is also used, into a pulper 101containing forming liquid, such as an aqueous forming liquid, flowing ina return pipe 107. Mixing takes place in the pulper 101 with an agitator103 to form a relatively concentrated slurry that exits the pulper 101through pipe 109 and into a pump 111 that pumps the concentrated slurryinto a holding tank 113. The forming liquid is delivered to pipe 107 bypump 125, pumping the forming liquid coming from a pipe 123 and adeairing tank 121. Concentrated slurry is metered out of the holdingtank 113 by a pump 115 and variable flow valve 114 where theconcentrated slurry is diluted substantially with the forming liquidcoming through pipe 126 to a forming pump 127. The substantially dilutedslurry, may have a solids concentration of less than about 0.04 percent,flows through pipe 116 to a distribution manifold 112 on a forming box117.

The slurry flows toward a moving permeable forming belt 20 where thefibers and any particulates in the slurries are formed into a wet,nonwoven web while the forming water flows through the forming belt asreturn forming liquid 119 and onto the deairing tank 121. A finalsuction tube assembly 129 under the forming belt 120 near where the wetweb is removed from the forming belt 120 removes excess forming liquidfrom the wet web and returns it through pipe 132 to the de-airing tank121. The wet web is then transferred to a second moving permeable belt130 that carries the wet web under an applicator 135, such as a curtaincoater type, where a sizing, with or without a binder is applied in anapplication section 131. Excess sizing and/or binder is removed from thewet, fibrous web or mat with suction tube assemblies 139 and 141 toreduce the sizing and/or binder level in the wet web to the desiredlevel. The coated web is then transferred to an oven belt 142 and passedthrough an oven 157 where the mat is dried and any film former resin(s)in the sizing and/or binder are cured. The dry mat 158 may then be woundinto a roll 159 for packaging or use nearby.

The fibers in the mats containing an optional binder are bound togetherwith a resinous binder, but the nonwoven mat need not contain any binderother than optional film former in the sizing. The binder may be anaqueous mixture of water and one or more resins or polymers and otheradditives in a solution, emulsion or latex. The sizing, binder orcombination is prepared by adding one or more ingredients 151 with aliquid 152, such as water, to a mix tank 147 containing an agitator 149.Excess binder, sizing or mixture removed from the wet web with suctionboxes 139 and 141 may also be added to the mix tank 147 by way of returnpipe 143. The mixed sizing, binder or mixture of the two is then pumpedwith pump 153 to a holding tank 145 to supply an applicator pump 146that meters the sizing, binder or mixture of the two at the desired rateusing variable valve 144 to the applicator 135.

In certain embodiments, a second sizing may be added to the fibers in anonwoven mat or in a woven fabric. FIG. 5 shows another system useful inadding one or two sizing compositions to the reinforcement fibers in anonwoven mat or a woven fabric. This system may be used as analternative to the sizing application disclosed above in the descriptionof FIG. 4, or in addition to that system to add a second sizingcomposition after the first sizing has been dried on the fibers in thenonwoven mat. For woven fabrics, the system of FIG. 5 may be used to addone or two different sizing compositions to the woven fabric as thefabric comes off of the loom, or in a separate step.

When used with the wet process in FIG. 4, a dryer chain/screen 204carries the wet to dry, hot nonwoven mat 201 through the dryer 200driven by a tail pulley 206 mounted on axle 208. The hot, dry mat 203exiting the dryer may then be wound up into rolls 220 on a mandrel 218supported by arms 219 of a winder, such as an indexing winder. Otherrolls 212, 216 and at least one movable accumulator roll 214 provideenough slack to allow the winder to doff the mat, rotate a finished roll220 out of position and a fresh mandrel into winding position to startwinding a new roll 220. Nonwoven mats may also be made by a dry processand mats made by dry processes may include dry chopped fiber mats andcontinuous filament mats.

The woven or nonwoven fibrous mats may be very permeable due to the manyrelatively large pores in the surface and throughout the mats. Thepermeability of these mats is in the range of about 50 to about 1500.For example, the permeability of the mats may be in the range of about175 to about 1000 or about 200 to about 800 cubic feet per minute persquare foot (ASTM D737 test method).

Referring to FIG. 5, instances where the bottom surface of nonwoven mat,woven or nonwoven scrim and/or woven fabric 203, coming out of an oven200 as the final step in the process of making such fibrous materials,may be coated with a size composition, such as using a roll over rollcoater 223. In a roll-over-roll coater 223 a first roll 225 rotates in apan 222 containing the liquid size 224, a liquid, where the liquid maybe a water medium, and picks up a layer of the size 224 on the surfaceof the roll 225 and transfers the layer of size 224 to a second, coatingroll 226. The coating roll 226 “kisses” the back side of the mat orfabric 203 transferring the size to the fibers, and optionally bindercoated fibers, in the mat or fabric. The amount of size applied to themat or fabric may be controlled by adjusting the concentration of thesize 224 and by controlling the amount of liquid size picked up by thefirst roll 225. The size quickly is moved through the mat or fabric bythe size wanting to wet the fibers and then heating with one or moreheaters 233, such as a hot air heater, drives off the water or solventin the sizing, leaving the caprolactam PI on the fibers or the curedbinder coating the fibers. The penetration of the surfactant into themat or fabric to the opposite surface is completed by varying one ormore of the non-isocyanate PA concentration in the size 224, the amountof size applied to the mat or fabric 203, the temperature of the hot airin the one or more dryers 233, and the speed of the tail pulley 206.

If additional or more size is desired on the mat or fabric than may beapplied with the coater 223, one or more optional other coating devices227 can be used, either in the place of the coater 223 or in addition tothe coater 223. For example, one or more spray jet coaters 227 comprisedof a manifold 28 and spaced apart jet nozzles 30 can be used. Forexample, jet nozzles that form a mist or atomize the size 224 may beused. This system may also be used to apply a size containing one ormore precursors for the non-isocyanate PA to the mat or fabric 203.

In embodiments where the fibers in the mat or fabric 203 have a secondsize containing a different non-isocyanate compound PA or precursor forsuch applied prior to final drying, a second set of size applicators227″ are shown followed by one or more secondary dryers 234. The dryers233 and 234 may be located adjacent both surfaces of the mat or fabric203 if desired. The dryers may be of any suitable type, such as hotforced air heaters, surface combustion heaters or infra-red heaters. Incases where size transfer doesn't matter, it is not necessary that themat or fabric be completely dry prior to winding into the roll 220, orprior to stacking sheets of the mat or fabric together. Where it isbeneficial to apply size 224 to the top surface of the mat or fabric203, the application equipment is arranged to coat that side instead ofthe bottom side, using for example, jet spray applicators 227, 227″.

The present embodiments simplify the RTM, RIM, VARTM/RIM, (vacuumassisted RTM or RIM), pultrusion, injection molding and filament windingsystems and processes by placing the PI and/or catalyst on the surfaceof the particles of filler and/or pigment and/or on the reinforcementfibers and/or flakes. The cost and added complexity of the equipmentneeded such as additional resin tanks, heaters, pumps, lines, valves,mixers, etc., and the elimination of such equipment means that themaintenance costs including cleaning and mixing, are substantiallyreduced. In particular, a process such as Reactive Injection Moldingthat comprises a modified vertical/horizontal injection molding processis significantly simplified by using a reactive glass surface. Atwo-component system presents processing challenges for this process dueto the difficulties in achieving uniform mixing in an injection moldingscrew design.

Reactive glass for PA, PBT, PU, other thermosets and thermoplastics maybe used as the reinforcing material to create composites using thereactive injection process in a one-pot system.

Where the complex systems currently exist, the present embodiments freeup one or more monomer or monomer mixture portion of the system topermit the molding system to make laminate or over-molded parts and/orproducts by using the first shot to make a Nylon 6 or PBT core or layerand then at the appropriate time, having used the other monomer ormonomer mixture equipment to make a second shot of polyurethane or PBTto produce a outer surface or second layer having enhanced propertiesincluding one or more of moisture absorption, smoothness, hardnesslevel, etc. In other embodiments a strong thermoset core may beover-molded with a more impact resistant, tougher thermoplastic shell.The examples will describe some of the options for making differentcomposite laminates and parts using a multi-component system where thefiller, pigment and/or the reinforcing material is reactive and may befor example, a glass material.

Example 1

Glass fibers or flakes in the form of a woven fabric or non-woven mat ora combination of both are placed in a mold. Several layers of fabric ormat are used to achieve a glass loading of >50%. The glass contains 1 to3% by weight of triethoxypropylsilane isocyanate-capped caprolactamresidue PI on the reinforcement surfaces. The PI is bonded to the glassvia the silane linkage. Using a reactive injection molding process inthe horizontal or vertical configuration, a mixture of caprolactam andsodium caprolactam catalyst (1-3% by weight with respect to caprolactam)is injected using a one-pot system. The mixture is fed as a solid and itmelts during the transfer process wherein the screw elements convey themixture to the mold and the mixture is injected into and wets the glassfiber fabric layers in the mold. The mold is maintained at 160° C. andpolymerization is allowed to occur for 4-10 minutes. The resultantproduct is a glass reinforced Nylon 6 composite.

A variant of this example is the process of making a glass fiberreinforced PBT composite. In this case, the glass fibers have on theirsurfaces 0.5-3 wt. %, based on the dry weight of the fibers, ofchlorobutyltindihydroxide catalyst. Cyclic butylene terephthalatemonomer is then injected into the shaped glass fiber fabric using theone-pot injection molding system, which is suitable because of the useof reactive fibers. Polymerization is allowed to occur in the mold at190-210° C. for 4-10 minutes to produce a glass fiber reinforced PBTcomposite.

Example 2

In a two-component injection/infusion system, glass fibers sized with asilane based PI compound for caprolactam polymerization are placed in amold which is maintained at 160° C. The silane based PI is the reactionproduct of mercaptopropyltrimethoxysilane and acryloyl caprolactam andis present in the range of 1 to 3 wt. % based on the dry weight of theglass fibers, on the glass fiber surfaces as a dry residue. From onemelting vessel, caprolactam mixed with a magnesiumbromide-caprolactamcatalyst (2 to 4% by weight) is injected/infused in to the reactiveglass fibers previously placed into the mold and polymerization wasallowed to occur. After allowing sufficient time for completion ofpolymerization (4-10 minutes), the mixture from the second meltingvessel, comprised of cyclic-butylene terephthalate monomer and atetraisopropyl titanate catalyst (0.3 to 2% by weight) isinjected/infused over the polyamide composite. This mixture thenpolymerizes in the mold at 190-210° C. and forms a PBT over-layersandwiching the polyamide composite. This sandwich structure providesthe benefit of a tough polyamide core with a strong PBT shell over orsurrounding the core.

Example 3

This example is similar to Example 2, and is for an injection-basedpultrusion process. Continuous reactive glass fibers in the form ofreactive rovings and/or reactive glass mat and/or reactive glass fiberfabric, sized for polyamide polymerization by comprising of 1-3 wt. % ofa residue of hexamethylenediisocyanato-capped caprolactam PI by weight,are pulled through a die. A mixture of caprolactam and Na-caprolactamcatalyst (1 to 3% by weight) is injected into the reactive glass fibersto cause polymerization at 160° C. with a sufficient pulling speed toallow 4-10 minutes for polymerization to occur. At a further point alongthe die, the mixture of cyclic butylene terephthalate monomer and 0.5 to2 weight % of dibutyltin dioxide catalyst is injected to form a layer ofPBT over or surrounding the PA 6 composite and heated at 190-210° C. topolymerize the PBT. The pulling speed and die length are adjusted toallow 4-10 minutes for the PBT polymerization process. Optionally, thecomposite goes through a post-curing process either in a continuousmanner in a die or as a stand-alone process in an oven at 160-200° C. tocomplete the polymerization.

Example 4

In a 3-component injection/infusion system, reactive glass fiberscontaining a 1 to 3% N-mercapto ureido (caprolactam-capped tolueneisocyanate) propyltrimethoxysilane PI, for PA 6 polymerization, residueon their surfaces are made into a fabric, shaped and fixed in a mold.Caprolactam, mixed with 1 to 3% Na-caprolactam catalyst in the moltenform was injected from one pot into the reactive fabric andpolymerization was allowed to occur on the surfaces of the glass fibersat 160° C. for 4-10 minutes producing a glass fiber reinforced PA 6composite part. Over that composite part, a standard thermoset materialsystem such as Epoxy/Polyester/Vinylester was processed in a two-potprocess that included the resin and the hardener. The thermoset matrixwas then formed over the PA 6 core providing a hard surface over atough, glass fiber reinforced PA 6 inner core material.

Example 5

Similar to example 4, but the glass fibers were sized with 0.5 to 3% ofchlorobutyltindihydroxide catalyst for CBT polymerization to formreactive fibers. These reactive glass fibers, in the form of rovings oryarn were then woven into a fabric and this reactive glass fiber fabricwas then placed in a mold in a way to form a reinforced part. Next,cyclic butylene terephthalate was injected/infused over the reactiveglass fabric and polymerization of PBT was allowed to occur at 190-210°C. for 4-10 minutes. Finally a thermoset matrix was then formed over theglass-reinforced PBT core. In a modification of this embodiment, thethermoset matrix contained reactive glass fibers having a catalyst as aresidue of a sizing containing the catalyst on the surfaces of thefibers. Other modifications used reactive glass flakes in place of thereactive fibers in either the first step, the overlay step or both.

Example 6

This example was similar to examples 4 and 5, but instead of theepoxy/vinylester/polyester systems, a polyurethane system was processedover the glass-reinforced thermoplastic core.

Example 7

In a first step a glass fiber fabric with the reactive component residueon the fibers was placed in the mold and the monomer was injected toreact with the reactive component to form a reinforced thermoplasticcomposite core layer. The mold was built as a two cavity turntable thatcould rotate 180°. A second layer of a different reactive reinforcementmaterial such as a reactive glass fiber nonwoven mat and/or a reactiveglass fiber nonwoven surface veil was placed in the second outer part ofthe mold and surrounded the core after closing the tool. Then a secondcomponent of monomer (different chemistry or similar chemistry butmodified such as pigmented, toughened, or other type of modification)was injected into the reactive glass fiber nonwoven mat and/or veil.

The first reactive component was glass fibers sized with 0.5 to 3%benzoyl caprolactam PI. The injection mixture was comprised ofcaprolactam monomer and 1-4% MgBr-caprolactam catalyst, andpolymerization was allowed to occur at 160° C. for 4-10 minutes.

The second reactive component was a glass fiber sized with 0.5 to 3%tributyltin ethoxide catalyst. The monomer mix was comprised ofcyclicbutylene terephthalate and other additives such as fillers andpigments. The polymerization conditions were 190-210° C. at 4-10minutes.

Example 8

A part was produced in a manner similar to that of Example 7, but inthis case, a foam was used in parts of the component. The foamingcomponent, e.g. a thermoplastic with a foaming agent or with gasfoaming, was injected first into the mold and allowed to expand. Thenthe second molding step included the reactive reinforcing material andthe monomer was injected in an additional space surrounding the foamedmaterial.

Example 9

In cases where using Example 8 is not desirable because the foam wouldcollapse due to the reaction temperature of the monomer, this exampleoffers a solution. To avoid the foam collapsing, the reactivereinforcement material is placed first and the monomer was then injectedinto the reactive reinforcement to form the reinforced polymercomposite. Those portions where a foamed material was desired was keptopen by the use of removable cores or blocks in the shape of the desiredfoamed portion(s). The cores were then moved out of the mold and thefoaming material was injected filling the voids left by the cores.Instead of cores or blocks, a second tooling half using a rotationalmold could be used.

A multitude of other embodiments are possible including, but not limitedto, using reactive fillers and pigments in place of or in addition tothe reactive fibers and/or flakes and with non-reactive fibers and/orflakes. The fibers, flakes, filler particles and pigment particles maybe of any material used to reinforce, stabilize and/or color and/or totexture thermoplastic and thermoset composite parts or products.

What is claimed is:
 1. A method of forming a multi-component reinforcedcomposite, the method comprising: forming a first particle-reinforcedcomponent in a mold, wherein the first particle reinforced component isformed by a first process comprising: providing in the mold reactiveparticles that have a reactive polymerization promoter chemically bondedor coated on a surface of the reactive particles; contacting thereactive particles with a first resin solution comprising monomers of apolymer, wherein the polymerization promoter promotes the polymerizationof the monomers; and polymerizing the first resin solution to form apolymer matrix around the reactive particles and form the first particlereinforced component; and forming a layer of a second polymer-containingcomponent in contact with the first particle-reinforced component,wherein the layer of the second polymer-containing component in contactwith the first particle-reinforced component is formed by a secondprocess comprising: contacting the first particle-reinforced componentwith a second resin solution comprising monomers of a polymer; andpolymerizing the second resin solution in the mold to form the secondpolymer-containing component, wherein: the second process is a thermosetprocess selected from the group consisting of reactive injectionmolding, structural reactive injection molding, resin transfer molding,vacuum-assisted resin transfer molding, reactive long fiber injectionmolding, reactive sheet molding compound, and reactive bulk moldingcompound, the second polymer-containing component comprises athermoplastic polymer, polymerizing the second resin solution occursduring contact with the first particle-reinforced component, and thelayer of the second polymer-containing component surrounds a corecomprising the first particle-reinforced component.
 2. The method ofclaim 1, wherein the polymerization promoter comprises a polymerizationinitiator that initiates the polymerization of caprolactam monomers, andwherein the resin solution comprises caprolactam monomers.
 3. The methodof claim 2, wherein the first resin solution further comprises apolymerization catalyst.
 4. The method of claim 1, wherein thepolymerization promoter comprises a polymerization catalyst thatcatalyzes the polymerization of cyclic 1,4-butylene terephthalate (CBT)into polybutylene terephthalate (PBT).
 5. The method of claim 1, whereinthe reactive particles comprise glass fibers or glass flakes sized witha sizing compositing comprising the polymerization promoter.
 6. Themethod of claim 1, wherein the method further comprises activating thepolymerization promoter on the surface of the reactive particles to makethem the reactive polymerization promoter.
 7. The method of claim 1,wherein the second polymer-containing component is a particle-reinforcedcomposite comprising reinforcing fibers or flakes.
 8. A method of makinga glass reinforced composite, the method comprising: forming a firstglass-reinforced component, wherein the first glass reinforced componentis formed by a first process comprising: providing glass fibers thathave a reactive polymerization promoter chemically bonded or coated on asurface of the glass fibers; contacting the glass fibers with a firstthermoplastic resin solution comprising monomers of a polymer, whereinthe polymerization promoter promotes the polymerization of the monomers;and polymerizing the resin solution to form a polymer matrix around theglass fibers and form the first glass-reinforced component; and forminga second polymer-containing component in contact with the firstglass-reinforced component, wherein the second polymer-containingcomponent is formed by a second process comprising: contacting the firstglass-reinforced component with a second thermoplastic resin solutioncomprising monomers of a polymer; polymerizing the second thermoplasticresin solution to form the second polymer-containing component, wherein:the second process is a thermoset process selected from the groupconsisting of reactive injection molding, structural reactive injectionmolding, resin transfer molding, vacuum-assisted resin transfer molding,reactive long fiber injection molding, reactive sheet molding compound,and reactive bulk molding compound, polymerizing the secondthermoplastic resin solution occurs during contact with the firstglass-reinforced component, and the second polymer-containing componentsurrounds the first glass-reinforced component.
 9. The method of claim1, wherein the first particle reinforced component comprises apolyamide.
 10. The method of claim 1, wherein the secondpolymer-containing component comprises polybutylene terephthalate. 11.The method of claim 9, wherein the second polymer-containing componentcomprises polybutylene terephthalate.
 12. The method of claim 1, whereinforming the first particle-reinforced component further comprisesinjecting a foam into the mold.
 13. The method of claim 8, whereinforming the first glass-reinforced component further comprises injectinga foam into a mold.
 14. The method of claim 7, wherein the reinforcingfibers or flakes are not sized with a polymerization initiator.